The male gamete could not unite with the female.雄配子不能与雌配子结合.Gametes may develop without fertilization, or meiosis may substantially precede gamete formation.配子不经过受精也可能发育,若减数分裂先于配子形成,配子也可能发育.Objective : To investigate the...
雕刻刀: 雕刻铜版用的槽形钢刀.Graver: V - shaped steel cutting tool used by engravers . Also called burin.凹版印刷包括照相凹版,模型压印, 铜版凹印和移印.It includes gravure, die stamping copper - plate engraving and pad printing.这些铜版本身也还来不败为很宝贵的艺术品.These a...
The medical term for this condition is " intermittent claudication. "这个症状的医学术语是 “ 间歇性跛行 ”.About 10 percent of people with PAD have intermittent claudication.大约10%的PAD患者会出现间歇性跛行的症状.Early symptoms: cold limbs, numbness, pa...